M8 focus shifts and "back focus"

[charlesphoto99]

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If I might be so bold as to sum up much of what has gone before. There are two basic situations of using lenses with digital bodies. One we can live with, the other requires either the lens to be serviced/adjusted or replaced. The following assumes that the rangefinder and linkage in the body itself, are correctly adjusted at infinity, middle and near distances. Situation one is where the focus point remains sharp within the defined COC field of focus at all distances/apertures but the distribution of the depth of focus changes either side of the focus point, as distance or aperture is varied. Situation two is where the rangefinder point of focus is unacceptably out of focus at any selected distance or aperture. Situation one we can learn to live with. Situation two you can't and the lens has to be adjusted or changed.

 

Sadly my Noctilux appears to be situation two and will have to go for another holiday in Solms. I tried playing around with the focus cam in the body yesterday and could either get it right at middle distances but wrong at infinity or vice versa but not both right. When it was right at infinity, that was also the correct cam setting for my Elmarit-M 90 at both infinity and middle distances.

 

Wilson

 

I said here again and again on a prvious focus thread (and Carsten was the first to point this out) that it is not enough to just adjust the infinity cam, at least in some cases. This was true with my first M8 body. I also needed to adjust the near/far cam (an elliptical screw located at the beginning of the arm) as when I adjusted only the infinity, my middle distances wouldn't focus correctly. Doing a fine dance between the two adjustments is what is neccesary, at close in, middle, and far.

 

My new body seems to focus properly, though it is an early serial chrome, and I suspect a refurb (I think Leica's using refurbs as replacements. I don't mind so long as everything works). I am still having stop down backfocus issues with my 35 Lux asph and to a lesser degree my 50 pre-asph lux (already shimmed by DAG). I think it's just the way it's going to be with some lenses, unfortunately.

 

I just shot a job on bike messengers - the art director wanted b&w film so I used my M7 (good thing anyway as it's still under 5 year passport and I had to ride along with a messenger). There are so many slightly out of focus shots that are still entirely usable. Not for any mecahnical reasons, just due to the nature of the subject and style of shooting. It really is the difference between film and digital. I also think many users, on this forum at least, are now expecting the M8 to replace their Hasselblads, etc. and traditionally that has never been the role of M cameras. I am actually more interested in replicating what my M7 can do with the M8 vs besting it. To that end I'll be using Alien Skin, etc. I prefer the look of film, just not the cost, car trips to the lab, etc, etc. I actually find the resolutionof the M8 to be too much in a lot of circumstances in that it does show up every flaw in focus, lighting etc that we would'nt have noticed shooting Tri-X.

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[wlaidlaw]

I said here again and again on a prvious focus thread (and Carsten was the first to point this out) that it is not enough to just adjust the infinity cam, at least in some cases. This was true with my first M8 body. I also needed to adjust the near/far cam (an elliptical screw located at the beginning of the arm) as when I adjusted only the infinity, my middle distances wouldn't focus correctly. Doing a fine dance between the two adjustments is what is neccesary, at close in, middle, and far.

 

My new body seems to focus properly, though it is an early serial chrome, and I suspect a refurb (I think Leica's using refurbs as replacements. I don't mind so long as everything works). I am still having stop down backfocus issues with my 35 Lux asph and to a lesser degree my 50 pre-asph lux (already shimmed by DAG). I think it's just the way it's going to be with some lenses, unfortunately.

 

 

 

 

Charles,

 

I am terribly reluctant to play with the near and middle distance focus as there is no problem with my Elmar-M 50, Elmarit-M 90 or Zeiss Biogon 35 lenses. The DOF on my Biogon 21 is so huge it is not very relevant to focus issues. I did not expect my playing around with the infinity cam to improve my Noctilux as Infinity was OK to start with. It was really to see if I could get it focus consistently at middle distances, which I could if I were to accept that all my other lenses would be wrong at all distances. The middle distance on my Noctilux is out by such a huge margin (nearly 2m at 8.5m) that I am sure that there is an internal problem with the lens. Leica UK seemed to agree. They said that the focusing will struggle at the very near end but in fact it is not too bad with the rangefinder focus point just about inside the depth of focus at 1m and f1.0. I am not too worried about this but the 3-10m range is exactly where I expect to be using the Noctilux and I have bought an f1.0 lens to use as an f1.0 lens.

 

Mine too is an early serial chrome although this was sold as a new camera in January and was not a replacement. Leica confirmed that it was an upgraded sensor model. I suppose if it is factory re-manufactured it is OK but I just have a slight niggle about it, when I bought what I thought was a wholly new camera.

 

Wilson

[charlesphoto99]

Wilson,

 

Yeah, sounds like your lens is the problem. On my first body, all the lenses were off, even the problem free 24mm.

 

Yeah, I was a bit perturbed that Leica replaced my black late serial M8 with an early chrome. Of course I had grounds to complain re the color switch, but I fell in love with the silver, a finish I had never even contemplated (I am a pro after all - ha!). But everything on the camera was so much smoother then my original lemon that I'm happy with it. Also tired of shipping fees and waits, and who knows what a replacement of a replacement might bring. I say once you get a good one hang onto it (well at least until any hidden gremlins might pop up).

 

Charles